1. Field of the Invention
The present invention is related generally to baking, and more particularly to a method and apparatus for monitoring the doneness of a baked product.
2. Description of the Background Art
A baked product is typically a food product that has been exposed to heat (e.g., a dry heat) in order to cook the product from the outside. The baked product is not considered to be finished baking (i.e., done) until its interior is baked. The ability to detect when an item is completely and optimally baked is of great importance in the baking industry. When a bread product for example is completely baked, the gluten in the flour is transformed and the starches contained in the product are gelatinized. The exterior of such a baked product may acquire a shell, while the interior may take on a generally firm consistency. The presence of flour in an item enables it to be baked--e.g., the baking process can serve to polymerize the gluten in wheat and transform it into a firm, spongy structure. The polymerization of gluten is a physical change that can occur when baking bread products (polymerization is a chemical reaction in which small molecules are combined to form large molecules).
Several monitoring approaches for determining the optimal baking time have historically been employed by those in the art. The most popular and age-old method has been simply to bake an item for a fixed time and at a fixed temperature, based on an average time required to bake an item. Another method has been to insert temperature probes into the interior of the item, with baking being halted when the interior of the item reaches a predetermined temperature. A less preferred method has involved cutting or breaking open the item to visually inspect the doneness of the center of the product. Yet another visual monitoring method has been to observe the product exterior for a sufficient change in color. However, each of these prior approaches has significant drawbacks.
First, timed baking has significant drawbacks because it does not account for variations in the baking process. These variations may include, for example, variations in temperature between baking ovens, variations in temperature at different areas inside an oven, variations in ambient humidity and air pressure, and variations in the amounts and qualities of the ingredients.
Second, temperature probes have been used to accurately monitor the internal temperature of a baked product, but they have drawbacks because they invade the product and require additional equipment that must be inserted into the product, removed therefrom, and cleaned.
Third, monitoring the outside color of the product has drawbacks because it attempts to determine the optimal baking time by observing changes in the color of the product. It is well known in the art, however, that the exterior of the product can potentially change color without the interior being done.
Fourth, destructive testing by cutting or breaking open the product in order to visually inspect the interior has drawbacks due to its invasiveness. It is impractical for commercial baking enterprises to intentionally destroy quantities of product in this manner. Destructive testing also requires additional work because the destroyed product must be visually inspected in order to judge its level of doneness.
Some experienced bakers can also judge the doneness of bread by manually tapping it on one side and obtaining a feel of the loaf (i.e., the movement thereof) and observing the sound created. This method, however, has obvious limitations, drawbacks and deficiencies due to human error and the like.
The inability of those in the art to automatically monitor the doneness of a baked product without contacting the product has often resulted in overbaking of the product in an effort to avoid underbaking. This is commonly done to avoid any health risks or consumer dissatisfaction associated with incomplete baking, but the color, texture, flavor, and potentially the nutritional value of the baked product may suffer. Because commercial bakers have been unable to automatically monitor a baked product during the baking process, they have traditionally had to overbake products in order to compensate for the above-described variables.
What is needed, therefore, is an improved method and apparatus for the automatic, non-invasive monitoring of the doneness of a baked product.